Bad way to run (4)
I believe the answer is:
amok
'bad way to run' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for amok that I've seen before include "A state of murderous frenzy" , "(Run) in murderous frenzy" , "'Wildly, without self-control (4)'" , "Running wild" , "Uncontrolled or murderous way to run!" .)